4- benzene sulfonamide hydrochloride

Methyl-isoxazole-(3)-carboxylic acid chloride 4-(/3-Aminoethyl)benzene sulfonamide hydrochloride Chloroformic acid methyl ester N-Amlno-hexamethylene imine... 

There is obtained from 4-[)3-[5-methyl-isoxazolyl-(3)-carboxamido]-ethyl]-benzene-sulfonamide (prepared from 5-methyl-isoxazole-(3)-carboxylic acid chloride and 4-()3-aminoethyl)-benzene-sulfonamide hydrochloride, MP 213° to 214°C in pyridine) and chloroformic acid methyl ester, in a yield of 69%, the compound N-[ [-4-[)3-[5-methyl-isoxazolyl-(3)-carbox-amido] -ethyl] ] -benzene-sulfonyl] ] -methyl-urethane in the form of colorless crystals of MP 173°C. 

The submitters did not redistil the feri-butyl hypochlorite. If it is desired to avoid the use of feri-butyl hypochlorite, an equivalent quantity of dichloramine (N,N-dichlorobenzene-sulfonamide, Arapahoe Chemical Co., Boulder, Colorado) may be substituted. This material is soluble in benzene but the benzene-sulfonamide is not therefore the reaction mixture must be filtered just before the addition of the sodium methoxide solution. Using this technique, the submitters obtained 44-52% of phenacylamine hydrochloride. 

Procedure Sulfapyridine (0.3 g) is refluxed in a 10-ml ground-glass-joint flask with 4 ml of 25% HCl for 24 hr. The contents of the flask are poured into an evaporation dish and evaporated on a water bath to dryness. NaOH solution (10% 5 ml) is added to the residue and the mixture is extracted three times with 5 ml of benzene in a separatory funnel. The benzene extracts are dried thoroughly with solid sodium hydroxide and filtered through cotton-wool into a 25-ml dry flask. p-Toluenesulfonyl chloride (0.1 g) is added to the solution, followed by 1 ml pyridine, and the mixture is refluxed for 30 min. Five milliliters of benzene are then distilled off and the residue in the flask is filtered to get rid of the hydrochloride formed. After evaporation of benzene from the filtrate, sulfonamide is obtained, which is recrystallized from 6 ml of 50% ethanol. Yield, 22 mg mp, 214—216 °C. 

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